How can i make the cloth fold
In order to create such a 'folded' structure using the physics cloth simulation, there are two things you need : sufficient detail to your cloth mesh and sufficient 'spare' cloth to allow it to arrange itself into folds.

Without sufficient detail in your cloth you will old get coarse folds - there just isn't the geometry to create anything else. However, bear in mind that the more detail you add to your cloth mesh, the longer it will take to simulate. In my case I used the following heavily subdivided mesh as a base :



In order to create the 'spare' cloth you need to create it 'spread out' and then manipulate it to draw it together. This will naturally create 'folds' as there will no longer be sufficient space for the cloth - similar to when a real curtain is bunched togther. In order to achieve this you can 'pin' the sections of the cloth you want to manipulate and then use Shape Keys to manipulate them, leaving the rest of the cloth to behave as per the simulation.

Start by selecting all the 'top-edge' vertices. Create a new Vertex Group and 'Assign' the selected vertices to that group. Name the group 'Pin'.

In the cloth simulation, set 'Pin' as the group to use for Pinning.

Similarly, select the vertices at the bottom of the cloth that you want to manipulate, create another group named 'Hook' and 'Assign' the vertices to that group. Also assign them to the 'Pin' group (very important!!). The 'Hook' group can be used to conveniently locate your vertices, while the 'Pin' group tells Blender which vertices are being controlled independently of the simulation.

Next, add some shape keys - the first one is the 'Basis' key (the one all the others are based on). Add another shape key (Key 1) - this will affect the top edge. While Key 1 is selected, select the top row of vertices and scale them down to a point (S0Return). Now, adjusting the strength of Key 1 will draw the top vertices together.

It's also helpful to sepearately select the 'Hook' vertices (while still having Key 1 enabled) and also scale those to a point. In this way, as we use Key 1 to draw the curtain together the hook points will stay below the same point in the curtain.

Add another shape key (Key 2). Whilst it's selected, move the 'Hook' vertices to their desired location for raising the bottom edges (bring them forward slightly and 'up').

Now you can simply run the simulation while manipulating the Shape Key strengths. This should have an effect similar to the following :



Once you're happy with the motion, you can enable 'Self Collision' of the cloth simulation to ensure the folds behave consistently and don't intersect. However, note that this will considerably increase the time required to run the simulation.